Purgers, Air & Water - Air & Water Removal

APP Series Auto-Purger Plus

HM00APP__

Introduction

The AUTO-PURGER Plus is a totally automatic, electronically-controlled refrigerant noncondensible gas (air) and water purger for reducing the energy costs of operating an ammonia refrigeration system. All models are pre-assembled, pre-wired, insulated, and include an automatic water bubbler, a relief valve, and an isolation service valve package. Installation requires piping the foul gas line, low-pressure pumped-liquid line, low-pressure liquid return line, suction line, water bubbler fill and drain lines, relief valve vent line, water purge line to a customer supplied container, and power connection, and wiring the remote purge point solenoid valves. Purge point solenoid valves must be purchased separately and must be a minimum of ½" (13 mm) port size.

In addition, a computerized modelAPPCis available where a separate plant computer or programmable logic controller (PLC) is used to independently operate the various remote purge point solenoid valves.

Water contamination in an industrial ammonia refrigeration system can lower system efficiency, and increase the electrical costs required to run the system's refrigeration compressors. Ammonia refrigerant that is contaminated with water requires a lower suction pressure to maintain the same evaporator temperature than would pure ammonia refrigerant. The requirement to maintain a lower suction pressure than would be necessary if the water contamination were removed is a waste of electrical energy. For water removal, the AUTO-PURGER Plus has the following capacities:
5% system water concentration 3 gallons of water removed per day
10% system water concentration 5 gallons of water removed per day
20% or more system water concentration 7 gallons of water removed per day.

The internal surface area and flooded evaporator efficiency gives the AUTO-PURGER Plus two to three times the foul gas condensing capacity of an Armstrong Purger and 10 times the capacity of purgers with small electric hermetic compressors. In a system with normal noncondensible loads, all models will handle a 750 ton (2600 kW) ammonia plant at suction pressures below atmospheric pressure or a 1500 ton (5300kW) ammonia plant at positive suction pressures. The amount of noncondensibles in the system is based on many factors including age, maintenance practices, and operating temperature.

The number of purgers required for a system depends on the number of installed purge points. Twenty-four purge points is the maximum practical number per purger. For example, a system with 24 points set to purge for 10 minutes per point requires a 240 minute (4 hour) cycle. Each purge point can be purged 6 times a day. This may, or may not, be adequate. Therefore, a second purger should be used and the purge points divided equally between the two purgers.

The AUTO-PURGER Plus can operate over a wide range of condensing pressures. This is important for refrigeration systems that operate at low condensing pressures during cold ambient conditions.